Apparatus and method for water treatment

Abstract

An apparatus for use in a liquid treatment process, and a method of use is described. The apparatus comprises an inlet configured to be connected to a source of liquid to be treated and an outlet for discharging liquid from the apparatus. At least one liquid treatment vessel or conduit is disposed between the inlet and the outlet, and is arranged to expose liquid in the vessel to ultraviolet radiation in an advanced oxidation process reaction. A source of ultraviolet radiation extending along the liquid treatment vessel or conduit, such that an annular flow volume is defined in the vessel or conduit around the source of ultraviolet radiation. A rotary device is disposed in the annular flow volume and a drive mechanism drives rotation of the rotary device. The rotary device is operable to induce cavitation in a liquid present in the annular flow volume.

What is claimed is: 
     
       1. An apparatus for use in a liquid treatment process, the apparatus comprising:
 an inlet configured to be connected to a source of liquid to be treated; 
 an outlet for discharging liquid from the apparatus; 
 at least one liquid treatment vessel or conduit disposed between the inlet and the outlet, and arranged to expose liquid in the vessel to ultraviolet radiation in an advanced oxidation process reaction; 
 a source of ultraviolet radiation extending along the liquid treatment vessel or conduit, such that an annular flow volume is defined in the vessel or conduit around the source of ultraviolet radiation; 
 a plurality of rotary devices disposed in the annular flow volume, wherein each of the rotary devices comprises one or more vanes or blades, and wherein the plurality of rotary devices is distributed circumferentially around the annular flow volume; 
 and comprising a plurality of drive mechanisms, each drive mechanism arranged to drive rotation of a respective one of the plurality of rotary devices; 
 wherein the apparatus is operable to drive the plurality of rotary devices to induce cavitation in a liquid present in the annular flow volume at the circumferentially distributed positions of the plurality of rotary devices in the annular flow volume. 
 
     
     
       2. The apparatus according to  claim 1 , wherein each rotary device of the plurality of rotary devices comprises a plurality of rotary elements axially separated in the vessel or conduit, each rotary element comprising one or more vanes or blades. 
     
     
       3. The apparatus according to  claim 2 , wherein the axially separated rotary elements of one rotary device of the plurality of rotary devices are driven by a common drive mechanism of the plurality of drive mechanisms. 
     
     
       4. The apparatus according to  claim 1 , wherein at least one of the plurality of rotary devices is configured to generate a thrust on a liquid in the liquid treatment vessel. 
     
     
       5. The apparatus according to  claim 4 , wherein at least one of the plurality of rotary devices is operable to generate a thrust on a liquid present in the liquid treatment vessel, to cause liquid to flow from the inlet to the outlet. 
     
     
       6. The apparatus according to  claim 1 , wherein at least one of the plurality of rotary devices comprises one or more sacrificial components which wears, degrades or otherwise deteriorates as a consequence of cavitation induced by at least one rotary device. 
     
     
       7. The apparatus according to  claim 1 , wherein one or more components of the apparatus comprises aluminium. 
     
     
       8. The apparatus according to  claim 1 , wherein one or more components of the apparatus is partially or fully coated with a photocatalytic material. 
     
     
       9. The apparatus according to  claim 1 , wherein one or more components of the apparatus is partially of fully constructed from a photocatalytic material. 
     
     
       10. The apparatus according to  claim 8 , wherein the photocatalytic material is a composite of a polymeric material and a photocatalytic metal oxide. 
     
     
       11. The apparatus according to  claim 1 , wherein in use, at least one of the plurality of rotary devices is arranged to be disposed a distance less than 10 mm from a radiation-emitting surface of the source of ultraviolet radiation. 
     
     
       12. The apparatus according to  claim 11 , wherein in use, at least one of the plurality of rotary devices is arranged to be disposed a distance less than 5 mm from a radiation-emitting surface of the source of ultraviolet radiation. 
     
     
       13. The apparatus according to  claim 1 , comprising a support structure for at least one of the plurality of rotary devices. 
     
     
       14. The apparatus according to  claim 13 , wherein the support structure comprises a plurality of axially separated support elements which support a drive shaft of the at least one rotary device. 
     
     
       15. The apparatus according to  claim 14 , wherein the axially separated support elements comprise support plates, each support plate being configured to support multiple rotary devices of the plurality of rotary devices in the liquid treatment vessel or conduit. 
     
     
       16. A method of treating a liquid in an advanced oxidation process reaction, the method comprising:
 directing liquid to be treated through an annular flow volume around a source of ultraviolet radiation in at least one liquid treatment vessel or conduit; 
 exposing liquid in the vessel or conduit to ultraviolet radiation; 
 driving a plurality of rotary devices disposed in the annular flow volume, wherein each of the rotary devices comprises one or more vanes or blades and wherein the plurality of rotary devices is distributed circumferentially around the annular flow volume, to induce cavitation in the liquid present in the annular flow volume at the circumferentially distributed positions of the plurality of rotary devices in the annular flow volume. 
 
     
     
       17. The method according to  claim 16  comprising inducing cavitation in the liquid present in the annular flow volume at multiple locations axially separated along the source of ultraviolet radiation. 
     
     
       18. The apparatus according to  claim 2 , wherein the apparatus is operable to induce cavitation in the liquid present in the annular flow volume at multiple locations axially separated along the source of ultraviolet radiation. 
     
     
       19. The apparatus according to  claim 1 , wherein the plurality of rotary devices comprises blade elements, and a respective drive mechanism is operable to rotate the blade elements at a speed in excess of 5,000 rpm.